“It’s a secret,” Allison says softly, attempting to hide the fear in her eyes at the end of the special Halloween-flashback episode of the guilty-pleasure television hit “Pretty Little Liars.”

This line ironically sums up both the mystery of her own death as well as the show itself which, simply put, imparts more questions than answers. “The First Secret,” however, provides a break in the show’s circular nature by revisiting the past (specifically 2008, a year before Allison’s death). The episode connects events vaguely referenced in earlier episodes, all the while dropping little clues likely to prove relevant in the future.

A shocking revelation from the past is that “A” did not just appear to make the girls squirm after Allison’s death, but existed long before the events of the first season — harassing Allison as the first victim.

The rest of the flashback is filled with some fun scares and some fan-pleasing throwbacks: Hanna is “fat,” Emily is still in the closet, Aria has Hot Topic-approved pink clip-ins and Spencer wears large glasses to show she is smart. There is a haunted house with a Rosewood Sanitarium bus outside, odd people wander around in cloaks and baby-faced doll masks and Allison receives a creepy voodoo doll and a near-death situation, courtesy of a sharp knife aimed at her chest.

The addicting and complicated nature of the show is amplified and given a fresh twist with all 45-minutes given to the show’s barely seen, yet integral character,  Allison. Often portrayed as the standard manipulative Queen Bee of Rosewood, Allison shows vulnerability and fear beneath her façade of impenetrability. And if someone can scare Allison, does that mean they were strong enough to kill her as well?

Left longing for more by the end, the best TV-watchers can hope for is for the show to continue delivering more clues and revelations upon its return in January 2012. Until then, line up your conspiracy theories and give your best guess — who do you think “A” is?